As Mayor, he undertook the building of Auckland Museum and Cenotaph, the Wintergardens in Auckland Domain and the construction of Tamaki Drive. In later public life, he was responsible for the monument on One Tree Hill (Maungakiekie) and the treeplanting of Cornwall Park, fulfilling Sir Logan Campbell's vision. Gunson was Chairman of the Auckland Harbour Board 1911–15, and was a member of the Government Railways Board 1931–35.
Born and educated in Auckland, he took over the seed-grain business of his father, William Gunson. He stood several times for Parliament, unsuccessfully; (Mt Roskill in 1919, Eden in 1926 and then Auckland Suburbs in 1928).
Several parts of the city bear his name or gift. His farming property to the South of Auckland in Manukau, called Totara Park, was later given to the city of Auckland. His main town residence, in St Andrew's Road, Epsom, became the Tongan royal residence, which it remains. A further Auckland property (named Rydal Mount after the residence of the English poet William Wordsworth) was by the same architect, Draffin, that Gunson had chosen to design Auckland Museum. Gunson Street, in South Auckland, is named after him.
He married Jessie Helen Wiseman (later Lady Gunson OBE) in 1905. They had three children; William, Geoffrey and Margaret.
His brother Edward Burton Gunson MD FRCP (1883–1950) practised as a cardiologist in Auckland 1919–37. During World War One while in the RAMC EB Gunson assisted Thomas Lewis, the noted clinical scientist, in achieving an improved understanding of the Effort Syndrome. During World War Two Gunson worked for the Ministry of Supply in London publishing studies of women war workers' health.
- "Official jubilee medals". Evening Post. 6 May 1935. p. 4. Retrieved 14 August 2013.
- The Soldier’s Heart and the Effort Syndrome. Thomas Lewis. London 1918.
- EB Gunson. British Medical Journal 1942 ii 753-5. Communal feeding.
- Who’s Who in New Zealand, 4th edition 1941
- Who's Who (UK/World edition), 1954
- Entry in Dictionary of New Zealand Biography
|Mayor of Auckland City